327 Effects of Inclusion of Amaferm on Animal Performance, Chewing Activity, and Nutrient Digestibility of Backgrounding Beef Heifers Fed Either a Sorghum Silage- or a Byproducts-based Diet

Eighty-four Angus crossbred heifers (13 ± 1 mo, 329.5 ± 61.92 kg of BW) were used in a generalized randomized block design with a 2 × 2 factorial arrangement of treatments. The objective was to evaluate the effect of a feed additive inclusion under two growing diets. Factors included: 1) diet type (whole plant sorghum silage- or byproducts-based diet) and 2) feed additive inclusion [Amaferm (Aspergillus oryzae (extract)] included at 0 or 0.02% of the diet DM. This resulted in four treatments: sorghum-control (SC), sorghum-amaferm (SA), byproducts-control (BC) and byproducts-amaferm (BA). Heifers were housed in 12 pens (108 m2/pen; 7 heifers/ pen) equipped with GrowSafe technology, to measure individual dry matter intake (DMI). After a 14-d adaptation, BW was measured every 14 d, during 56 days, and chewing activity was monitored through collar-mounted HR-Tags (SCR Engineers Ltd., Netanya, Israel). Apparent total tract digestibility was measured on 10 heifers per treatment after the 56-d performance period, using indigestible NDF as a marker. Heifers fed the byproducts diet had (P ≤ 0.01) greater DMI as % of BW (2.92 vs. 2.59%) and greater average daily gain (1.16 vs. 0.68 kg/d). Amaferm improved gain-to-feed ratio by 15% in the byproducts diet (P ≤ 0.05) but it had no effect in the sorghum silage diet (P = 0.59). Conversely, Amaferm inclusion increased apparent total tract organic matter digestibility in the sorghum silage diet (SC = 49.8 vs. SA = 55.9%; P ≤ 0.01), whereas reduced it in the byproducts diet (BC = 65.8 vs. BA = 61.7%; P ≤ 0.05). Heifers fed a sorghum silage-based diet had (P ≤ 0.01) 39 and 63% greater chewing in min/d and min/kg of DMI, respectively; however, chewing in min/kg of NDF intake was similar across diets (average 111.3 min/kg of NDF intake).

Feed Intake Parameters of Horses Fed Soaked or Steamed Hay and Hygienic Quality of Hay Stored following Treatment

Horses suffering from equine asthma must consume low-dust forage, with soaking and steaming being suitable methods of hay treatment. The impacts of this treated hay’s subsequent storage and effects on the horses’ chewing activity are largely unknown. Meadow hay was soaked (10–15 °C, 15 min) or steamed (100 °C, 60 min). Microbial counts (colony forming units (CFU)) were determined by culture before and after soaking or steaming, and subsequent storage at 10 and 25 °C for 6, 12 and 24 h (three replicates each). Six horses were fed native, soaked and steamed hay, according to a cross-over design, and chewing parameters were measured. Steaming reduced (p < 0.05) typical mold vs. soaking (0 vs. 50 CFU/g) and yeasts vs. native and steamed hay (0 vs. 102 and 90 CFU/g). Storing soaked hay elevated bacteria, mold, and yeasts (p < 0.05). Within the first 60 min of hay intake, the steamed hay and soaked hay were eaten slower (19.5 and 21.5 g dry matter/min, respectively; p < 0.05) and the steamed hay was chewed more intensely (steamed hay: 3537; native: 2622; and soaked: 2521 chewing cycles/kg dry matter, p < 0.05). Steaming particularly improves the hygienic quality of hay. Soaked hay is not stable when stored and is less accepted by horses.

Behavioral Observation Procedures and Tests to Characterize the Suitability of Sows for Loose-Housed Farrowing Systems

The objective of the study was to evaluate behavioral observation procedures and tests to characterize sows’ behavior for their suitability for free farrowing systems. Nest building activity (NB), lying-down behavior (LDB), and position after lying down (PLD) were assessed. Four tests were designed to characterize the reaction of sows to a novel object and an unexpected situation (Towel Test, TT), behavior towards humans (Dummy Arm Test, DAT; Trough Cleaning Test, TCT), and behavior towards piglets (Reunion Test, RT). The study was performed on a nucleus farm in 37 batches including 771 purebred landrace sows housed in farrowing pens with short-term fixation. The assessment of NB started 2 days before the expected date of the farrowing. In 56.2% of the observations, the sows showed increased chewing activity on gunnysacks. The LDB and PLD were assessed on days 3 and 19 post partum (p.p.). In 49.1% of the observations, sows showed careful lying-down behavior. In 50.1% of cases, sows preferred the stomach-teats-position when lying down. With the DAT on day 4 p.p., in 89.3% of observations, no or only slight reactions of the sow were documented. The TT and TCT were performed on days 3 and 10 p.p. Strong defensive reactions of animals towards humans were recorded in 4.5% of the observations in the TT, and in 4.0% of the observations in the TCT. In the RT on day 3 p.p., in 61.8%, a joyful response of the sows to the reunion with their piglets was observed. This study showed that the behavioral observation procedures and designed tests are suitable to characterize sows’ behavior towards humans and piglets with regard to traits that are particularly important in systems without fixation.

197 Effect of a SARA challenge diet on chewing behavior and rumino-reticular short chain fatty acid concentrations in dairy cows

Intensive dairy production systems encourage feeding of high-concentrate diets to increase milk production efficiency. However, there is limited information regarding the effect of a SARA challenge diet on chewing behavior and rumino-reticular short chain fatty acid (SCFA) concentration. The objective of this study was to evaluate chewing activity and SCFA production in the rumen and reticulum, using nine ruminally cannulated non-lactating Holstein cows. Preceding the trial, cows were transitioned from 100% forage to 65% DM concentrate over eight days. Trial day 1 began once cows reached 65% DM concentrate and monitoring during 23 days. RumiWatch halters were used to monitor chewing activity. SCFA analysis was conducted on rumen and reticulum fluid collected 4 hours after feeding using gas chromatography. Data were analyzed with SAS, with the fixed effect of days and cow as random effect. There was an increase in DM intake during the first four hours after feeding: 1.97 and 2.25 ± 0.12 kg for day 1 and 23, respectively (P &lt; 0.05). There was no difference in rumination time (P = 0.16) with 29 ± 8.5 minutes during the first four hours of feeding. However, chewing index (P = 0.08) tended to decrease from 36.7 to 29.4 ± 4.4 minutes of chewing/kg of DM for day 1 and 23, respectively. Moreover, on day 1, propionate increased from 19.9 ± 1.02 to 20.1 ± 1.02% and from 24.04 ± 0.93 to 25.4 ± 1.02% compared to day 23 for rumen and reticulum, respectively (P &lt; 0.05). In addition, from day 1 to day 23, the rumen and reticulum acetate/propionate ratio declined from 3.2 ± 0.15 and 3.1 ± 0.1, to 2.5 ± 0.15, respectively, and reticulum SCFA decreased from 87 to 67 µmol/g, respectively. Overall, there was no effect of the 23-day SARA challenge diet on chewing activity. However, there was a reduction of SCFA concentration in reticulum, which may be due to enhanced SCFA absorption or increased feed bolus neutralizing capacity.

PSIV-23 Variations in chewing behavior and rumino-reticular pH in dairy cows during gradual adaptation to a high-grain diet

Physical effective fiber in the diet promotes chewing, contributing to the regulation of ruminal pH through saliva production, which leads to rumen health. However, lower dietary fiber content in high-grain diets may reduce rumination time and compromise ruminal pH regulation. The objective of this experiment was to evaluate rumination behavior and rumino-reticular pH variations during an 8-day adaptation to a 65% concentrate diet. For this study nine ruminally cannulated non-lactating Holstein cows were used. Prior to the initiation of the adaptation, cows were transitioned from a forage-only grass silage diet to a 65% DM concentrate diet over eight days. Rumination was monitored using RumiWatch halters (RumiWacthSystem ITIN+HOCH). Rumino-reticular pH was measured using eCow indwelling pH systems in five of nine cows recording data every 15 minutes. Data were analysed with SAS, the statistical model included day as fixed effect and cow was considered as random effect. Adaptation days had an effect (P &lt; 0.01) on rumination time, number of rumination chews per minute, and mean daily (rumino-reticular) pH. Especially, rumination time decreased from 439 to 327±62.8 minutes per day from day 1 to 8, respectively. Concomitantly, rumination chews per minute decreased from 68.8 to 65.6±2.06, and mean daily pH decreased from 6.54 and 6.26±0.07, respectively. Nevertheless, daily dry matter intake (P = 0.23) and eating time (P = 0.37) were not affected during the adaptation period. In conclusion, adaptation to a high-grain diet and the associated decrease in physically effective fiber gradually reduced chewing activity and ruminal/reticular pH. However, compared to the forage-only diet, significant reduction in rumination time was only noted at the 65% concentrate level.

Can eating harder textured foods slowly influence appetite?

IntroductionChewing a greater number of chews per bite has been shown to increase fullness, lower hunger levels and lead to a lower energy intake, when compared to chewing each bite fewer times. Increased levels of fullness and decreased levels of hunger have also been observed after consuming harder textured foods which require more chewing activity and have a longer oro-sensory exposure time. The aim of this study was to investigate whether consumption of foods differing in texture, classified as ‘fast’ or ‘slow’ foods, combined with differences in oral processing behaviours (chewing normally or more slowly), has an impact on self-reported hunger, fullness and satiety outcomes.Materials and MethodsThis is an interim analysis of a randomised crossover experiment designed to test the impact of both oral processing behaviours and food texture on self-reported hunger, fullness and satiety. Participants consumed two breakfasts of different texture (a ‘fast’ yoghurt and fruit compote option, and a ‘slow’ granola option) twice; once at their normal rate of eating and once after being instructed to eat slowly. Measures of self-reported appetite (hunger, fullness, satiety, desire to eat and prospective food consumption) were assessed using a visual analogue scale at three time points; baseline (minimum 20 minutes before consumption), immediately pre-consumption and post-consumption. Statistical analysis was conducted in SPSS; paired sample t tests and one-way analysis of variance was conducted to measure whether change in appetite ratings between the time points differed between the four breakfast options.ResultsData were collected from 16 healthy volunteers (study aiming to recruit n = 21; mean age 32.1 y, female n = 13, 81.3%). For all four breakfast options, levels of hunger, desire to eat and prospective food consumption significantly decreased, and levels of fullness and satiety significantly increased between both baseline and post-consumption, (p < 0.05) and between pre-consumption and post-consumption (p < 0.05). However, amongst the four breakfast options, no significant differences were observed in change in these appetite measures between baseline and post-consumption and pre- and post-consumption (p > 0.05).DiscussionThis interim analysis demonstrates no differences in mean change in appetite measures for breakfast options of different texture chewed normally or more slowly. Analysis of the full study will determine the effect of oral processing behaviours and food texture on self-reported hunger, fullness and satiety outcomes.